Jointed rule.



L. J. SWETT. JOINTED RULE.

APPLIOATION FILED MAY 11 1907.-

' Patented Oct. 4, 1910.

2 SHEBTFSHEET I L. J. SWETT.

JOINTED RULE.

API'LIOATION FILED Mn 11, 1901.

Patented 001;.4, 1910.

2 sums-sum a.

WnoLeR|sE|3'-q CENTER LINE o Ro witnesses fil'fomey nEvrJL swarm, orBURLINGTON, VERMONT.

JOINTED RULE.

Specification of Letters Patent.

Patented Oct. 4, 1910.

Application filed May 11, 1907. Serial No. 373,150.

To all whom it may concern.-

Be it known that I, LEVI J. Swn'rr, a citizen of the United States,residing at Burlington, in the county of Chittenden and State ofVermont, have invented certain new and useful Improvements in J ointedRules, of which the following is a specification, reference being hadtherein to the accompanying drawing.

My invention relates to improvements in that class of mechanicalinstruments, known as jointed rules, which have measuring scales; andthe object of my improvenlents is to provide a simple and reliableinstrument by means of which architects, building contractors,carpenters and roofers, especially,- can instantly and accuratelycompute the;

length of the hi s and valleys, as well as all measurements 0 aroof.

It consists of a hinged rule, of any con.- venient or desired len th,one limb, A, of which is divided into feet and inches, on a scale of onequarter of an inch to the foot; the inner edge of the other limb, B,being divided in the same manner, its outer edge into diagonal feet, andits center into octagonal feet, (22, 30), on the same scale. All partsof the rule are arranged to be read in inches by means of a Vernier k,at-

tached to the tapes C, C, which slide upon each limb of the rule. 0 is adouble Vernier on the slide M, of the limb ".B, to read the diagonalfeet in inches. The tapes 0, O, are of a length to correspond with thatof the limbs, and are so constructed that the may slide past each otherwithout di culty. They are each divided into feet and inches, and aremade of any suitable material; the slides L and .M, to which they areattached, being preferably made of metal so that they can always be heldat right angles to the limb upon which they slide. If desired, they canbe rigidly secured to the .limb by -suitable thumb-screws.

To enable my instrument to be more clearly understood, I refer to the.accompanying drawings, in which Figure l, is a plan view of my rule.Fig. 2, is a cross section of the limbs of my rule. Fig. 3, is a crosssection of the limbs, showing the connecting joint and the extension ofthe same for the clamp-screw. Fig. 4, is a half size plan view of myrule. Fig. 5, is a diagram of a part of a roof, drawnon the same scaleas Fig. 4, to illustrate the practical workings of my rule.

:(one-half of the width limbs of the rule, hinged atl, the movement Inthedrawings, A and B, are the two of the two limbs being controlled bythe thumb-screw H, which moves in a groove cut in the plates F extensionof the joint of the rule, by means of which the two limbs A and B may beset and held-at any angle to each other.

Slide L and slide M, of the tapes C, C,-

andG, on-the outside of the V four feet in width, with a rise of sevenand one half inches to the foot; first set the slide L, on the limb A,at 12 or 13 feet, as preferred, the rise of the roof being seven and onehalf feet in twelve feet, or fifteen feet in twenty-four feet. If set attwelve feet, then open the rule to seven and one-half feet on the tapeC, of the slide L, as shown in dotted lines in Fig. 4. This gives theslope of the roof (7% inches to the foot). Then move the slide L, totwenty-two feet, of the roof,) shown 1n Fig. 4, and it is instantlyfound that the rise on the slide is thirteen feet and nine inches, whichis the whole rise of the roof. At this point, on the inner edge of thelimb B, we read twenty-six feet, which is the length of the slope. Inthis way, by moving the slide L toward the hinge, the length of all ofthe shorter rafters may be found at once.

. To find the length of any hip or valley, I

in the same roof, set the slide M on the limb B- at twenty-two,(diagonal). feet, designated on the outer. edge of the limb B, and thebase line of the hip or valley is instantly given, asthirty-one feet andone and threeeighths inches, on the inner edge of the limb B, withoutthe necessity of any special plan or diagram.

Bring the limbs of the rule toward each other until the limb A, meetsthirteen feet and nine inches, and it is found, on the limb A, that thelength of the hip or valley will be thirtyfour feet and one-quarter ofan inch.

All of the above measurements corre- (the whole rise of the roof,) r

rule in a spond with Fig. 5, which given to show ments will be varied,accordin to the dimeasure or miter of any number of "inches, vernierscarried by cent the mensions of the building; an gave any rise from oneto forty inc es.

Should it be desired to find the diagofnal eet and inches on an angleof.45, find that number of feet and inches on the outer edge of the limbB, and on the inner edge of t e same limb, exactly 0 posite', is thediagonal measurement song t for.

The center line of divisions on limb B, are octa onal feet, (angle 22and can be used in the same Having thus described my invention, what Iclaim 1s:

' 1. A rule consisting of two limbs A and B pivoted together at one end,means for holding the limbs in their adjusted position, slides carriedby the limbs and longitudinally movable thereon, flexible tapes carriedb the lower edge of the slides and divide on their inner edges into feetand the slides adjalimbs whereby the read in inches, the inner and outeredges of the limb A divided into feet and inches,

agonal feet and locking the limbs in way for octagonal roofs. 1

same can be the innenedge of the limb B divided into feet and inches,and its outer edge into diand the center of the limb B divided intooctagonal feet and inches on the same scale. 2. rule consisting of twolimbs A and B pivoted together, adjacent one end at their mner edges,outwardly extending plates carried by the limbs beyond the pivot andhaving registering seglmental slots, a thumb-bolt passing throug theslots and their adjusted position,

slides carried by the limbs and longitudinally movable thereon, flexibletapes carried by the lower edge of the adjustable slides andflush-therewith, whereb they pass under the limbs and upon which thelimbs rest, said tapes divided on their inner'edges into feet andinches, the inner and outer edges of the limb A divided into feet andinches,

the inner edges of the limb B divided into feet and inches and its outeredge into diagonal feet and inches on the same scale, and the center ofthe limb B divided into octagonal feet and inches on the same scale. Intestimony whereof I do afiix my signature in presence of two witnesses.

LEVI J. SWETT.. Witnesses:

CHARLES H. GRANDALL, EDWARD E. MORGAN.

inches on the same scale, I

